/**
 * 
 */
package com.dfhc.util.aes;

import com.dfhc.util.StringHelper;

/**
 * @author 龙色波
 * java对应javascript的escape,unescape进行解码
 */
public class JsEncode {
	/*
	* 对应javascript的escape()函数, 加码后的串可直接使用javascript的unescape()进行解码
	*/
	public static String escape(String src) {
	   int i;
	   char j;
	   StringBuffer tmp = new StringBuffer();
	   tmp.ensureCapacity(src.length() * 6);
	   for (i = 0; i < src.length(); i++) {
	    j = src.charAt(i);
	    
//	    if (Character.isDigit(j) || Character.isLowerCase(j)
//	      || Character.isUpperCase(j))
	    if(Character.isDigit(j)||StringHelper.isLetter(j)){
	     tmp.append(j);
	    }else if (j < 256) {
	     tmp.append("%");
	     if (j < 16){
	      tmp.append("0");
	     }
	     tmp.append(Integer.toString(j, 16));
	    } else {
	     tmp.append("%u");
	     tmp.append(Integer.toString(j, 16));
	    }
	   }
	   return tmp.toString();
	}

	/*
	* 对应javascript的unescape()函数, 可对javascript的escape()进行解码
	*/
	public static String unescape(String src) {
	   StringBuffer tmp = new StringBuffer();
	   tmp.ensureCapacity(src.length());
	   int lastPos = 0, pos = 0;
	   char ch;
	   while (lastPos < src.length()) {
	    pos = src.indexOf("%", lastPos);
	    if (pos == lastPos) {
	     if (src.charAt(pos + 1) == 'u') {
	      ch = (char) Integer.parseInt(src
	        .substring(pos + 2, pos + 6), 16);
	      tmp.append(ch);
	      lastPos = pos + 6;
	     } else {
	      ch = (char) Integer.parseInt(src
	        .substring(pos + 1, pos + 3), 16);
	      tmp.append(ch);
	      lastPos = pos + 3;
	     }
	    } else {
	     if (pos == -1) {
	      tmp.append(src.substring(lastPos));
	      lastPos = src.length();
	     } else {
	      tmp.append(src.substring(lastPos, pos));
	      lastPos = pos;
	     }
	    }
	   }
	   return tmp.toString();
	}
}
